Cooling Strategies for Hyperthermia in the Elderly
Recruiting in Palo Alto (17 mi)
Age: 65+
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Academic
Recruiting
Sponsor: University of Texas Southwestern Medical Center
Disqualifiers: Heart disease, Cancer, Diabetes, others
No Placebo Group
Trial Summary
What is the purpose of this trial?The purpose of this study is to assess how well cooling modalities work in reducing cardiovascular stress of the elderly to heat wave conditions
Will I have to stop taking my current medications?
The trial does not specify if you need to stop taking your current medications, but it excludes people with chronic conditions that require regular medication.
What data supports the effectiveness of the treatment Cooling Strategies for Hyperthermia in the Elderly?
Research shows that wearing a water-soaked t-shirt without a fan can effectively reduce heat strain in older individuals in hot conditions. Additionally, active cooling methods, like evaporative cooling, are associated with lower mortality in severe heat illness cases.
12345Is it safe for elderly people to use cooling methods like fans and water-soaked clothing during heat exposure?
Research suggests that using a water-soaked t-shirt without a fan is a safe and effective way to manage heat in older adults, as it reduces sweat loss and heat strain. However, combining a fan with a water-soaked t-shirt may increase sweat loss without reducing heat strain.
13678How does the treatment for hyperthermia in the elderly using cooling strategies differ from other treatments?
This treatment is unique because it combines methods like using a fan, skin cooling, and water spray to manage heat in older adults, focusing on evaporative cooling, which is effective when air conditioning is not available. Unlike other methods like cold-water immersion, this approach is more accessible and practical for use in everyday settings.
13479Eligibility Criteria
This trial is for people aged 65 or older who are generally healthy, without significant medical issues based on a thorough check-up. It's not open to those with certain heart problems, a BMI of 31 or higher, chronic conditions needing ongoing treatment, known heart disease, current smokers or those who quit within the last three years.Inclusion Criteria
I am 65 years old or older.
Free of any significant underlying medical problems based upon a detailed medical history and physical exam
Exclusion Criteria
My heart screening showed possible signs of blocked blood flow or a new heart condition.
Current smokers, as well as individuals who regularly smoked within the past 3 years
My BMI is 31 or higher.
+3 more
Trial Timeline
Screening
Participants are screened for eligibility to participate in the trial
2-4 weeks
Treatment - Hot and Humid
Participants are exposed to a hot and humid climate chamber for 3 hours with different cooling modalities applied across four visits.
4 visits
4 visits (in-person)
Treatment - Very Hot and Dry
Participants are exposed to a very hot and dry climate chamber for 3 hours with different cooling modalities applied across four visits.
4 visits
4 visits (in-person)
Follow-up
Participants are monitored for safety and effectiveness after treatment, including evaluation of cardiovascular and thermal responses.
2-4 weeks
Participant Groups
The study is looking at how different cooling methods like fans and water sprays can help reduce heat-related cardiovascular stress in elderly individuals during heat waves. Some participants will use just a fan, others just a spray, some both together, and there'll be a control group with no intervention.
2Treatment groups
Experimental Treatment
Group I: Very hot and dryExperimental Treatment4 Interventions
Subjects will be exposed to 3 hours in a climate chamber set to approximately 47 deg C and 15% relative humidity, which reflects a very hot and dry heat wave condition similar to the 2018 Los Angeles heat wave. Four visits will be required to complete this arm, with each visit a different cooling modality applied.
Group II: Hot and humidExperimental Treatment4 Interventions
Subjects will be exposed to 3 hours in a climate chamber set to approximately 41 deg C and 40% relative humidity, which reflects hot and humid heat wave similar to the 1995 Chicago heat wave. Four visits will be required to complete this arm, with each visit a different cooling modality applied.
Find a Clinic Near You
Research Locations NearbySelect from list below to view details:
Texas Health Presbyterian Hospital DallasDallas, TX
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Who Is Running the Clinical Trial?
University of Texas Southwestern Medical CenterLead Sponsor
References
Keeping older individuals cool in hot and moderately humid conditions: wetted clothing with and without an electric fan. [2021]The present study evaluated whether wearing a water-soaked t-shirt, with or without electric fan use, mitigates thermal and cardiovascular strain in older individuals exposed to hot and moderately humid conditions. Nine healthy older individuals (68 ± 4 yr; five women) completed three 120-min heat exposures (42.4 ± 0.2°C, 34.2 ± 0.9% relative humidity) on separate days while wearing a dry t-shirt (CON), a t-shirt soaked with 500 ml of tap water (WET), or a t-shirt soaked with 500 ml of tap water while facing an electric fan (2.4 ± 0.4 m/s; WET+FAN). Measurements included core and skin temperatures, evaporative mass losses, heart rate, and blood pressure. In the WET condition, elevations in core temperature were attenuated compared with DRY from 30 to 120 min and compared with WET+FAN from 30 to 90 min (P < 0.05). Evaporative mass losses (inclusive of sweat and water losses from the shirt) were greatest in WET+FAN, followed by WET, and then DRY (P < 0.01). Sweat losses were lowest in WET, followed by DRY, and then WET+FAN (P < 0.01). Heart rate was lower only at 60 min in WET versus DRY (P = 0.01). No differences in mean arterial pressure were observed (P = 0.51). In conclusion, wearing a water-soaked t-shirt without, but not with, electric fan use is an effective heat management strategy to mitigate thermal strain and lower sweat losses in older individuals exposed to hot and moderately humid conditions.NEW & NOTEWORTHY In older individuals exposed to hot and moderately humid environments, electric fan use coupled with a water-soaked t-shirt exacerbates sweat losses without mitigating heat strain compared with a dry t-shirt. However, wearing a water-soaked t-shirt without fan use reduces sweat losses and attenuates heat strain compared with a dry t-shirt and a fan/water-soaked t-shirt combination. These findings suggest wearing a water-soaked t-shirt is an effective heat-management strategy for older individuals during heat waves when air conditioning is inaccessible.
Association between active cooling and lower mortality among patients with heat stroke and heat exhaustion. [2023]Body cooling is recommended for patients with heat stroke and heat exhaustion. However, differences in the outcomes of patients who do or do not receive active cooling therapy have not been determined. The best available evidence supporting active cooling is based on a case series without comparison groups; thus, the effectiveness of this method in improving patient prognoses cannot be appropriately quantified. Therefore, we compared the outcomes of heat stroke patients receiving active cooling with those of patients receiving rehydration-only therapy. This prospective observational multicenter registry-based study of heat stroke and heat exhaustion patients was conducted in Japan from 2010 to 2019. The patients were stratified into the "severe" group or the "mild-to-moderate" group, per clinical findings on admission. After conducting multivariate logistic regression analyses, we compared the prognoses between patients who received "active cooling + rehydration" and patients who received "rehydration only," with in-hospital death as the endpoint. Sex, age, onset situation (i.e., exertional or non-exertional), core body temperature, liver damage, renal dysfunction, and disseminated intravascular coagulation were considered potential covariates. Among those who received active cooling and rehydration-only therapy, the in-hospital mortality rates were 21.5% and 35.5%, respectively, for severe patients (n = 231) and 3.9% and 5.7%, respectively, for mild-to-moderate patients (n = 578). Rehydration-only therapy was associated with a higher in-hospital mortality in patients with severe heat illness (adjusted odds ratio [aOR], 3.29; 95% confidence interval [CI], 1.21-8.90), whereas the cooling methods were not associated with lower in-hospital mortality in patients with mild-to-moderate heat illness (aOR, 2.22; 95% CI, 0.92-5.84). Active cooling was associated with lower in-hospital mortality only in the severe group. Our results indicated that active cooling should be recommended as an adjunct to rehydration-only therapy for patients with severe heat illness.
Ice water submersion for rapid cooling in severe drug-induced hyperthermia. [2018]The optimal method of cooling hyperthermic patients is controversial. Although controlled data support ice water submersion, many authorities recommend a mist and fan technique. We report two patients with drug-induced hyperthermia, to demonstrate the rapid cooling rates of ice water submersion.
Heat-stroke: a review of rapid cooling techniques. [2019]Patients with prolonged hyperpyrexia due to heat-stroke have a poor outcome. Thus, the most important feature in the management of heat-stroke is rapid cooling. There are several methods of cooling available, such as fan therapy, cold water immersion, iced baths and evaporative cooling. Based on military and civilian experiences worldwide the development of protocols based on evaporative cooling is advocated as the most efficient.
Heat stroke : a review of cooling methods. [2018]The prognosis of heat stroke in patients is directly related to the degree of hyperthermia and its duration. Therefore, the most important feature in the treatment of heat stroke is rapid cooling. Several cooling methods have been presented in the literature including immersion in water at different temperatures, evaporative cooling, ice pack application, pharmacological treatment and invasive techniques. This article describes the various cooling techniques in terms of efficacy, availability, adverse effects and mortality rate. Data suggest that cooling should be initiated immediately at time of collapse and should be based on feasible field measures including ice or tepid water (1-16 degrees C), which are readily available. In the emergency department, management should be matched to the patient's age and medical background and include immersion in ice water (1-5 degrees C) or evaporative cooling.
Age Modulates Physiological Responses during Fan Use under Extreme Heat and Humidity. [2020]We examined the effect of electric fan use on cardiovascular and thermoregulatory responses of nine young (26 ± 3 yr) and nine aged (68 ± 4 yr) adults exposed to extreme heat and humidity.
Enhanced brain protection during passive hyperthermia in humans. [2022]Selective brain cooling during hyperthermia by emissary venous pathways from the skin of the head to the brain has been reported both in animals and humans. Heat protection of the brain extends tolerance to high deep body temperature in animals, and may be enhanced in humans if the head is cooled. In order to quantify to what extent brain protection could be obtained by face fanning, 9 non-anesthetized human volunteers were placed in ambient conditions as close as possible to those of passive therapeutic hyperthermia. Face-fanning maintained tympanic temperature 0.57 degrees C lower than esophageal temperature, and improved comfort. External head cooling techniques enhancing physiological brain cooling can therefore be useful for the protection of the human brain during heat stress or passive therapeutic hyperthermia.
Pediatric heat-related illness: recommendations for prevention and management [2019]Infants, children, and adolescents are at increased risk for heat-related illness due to their inability to remove themselves from dangerous environments. Evidence shows that morbidity and mortality from heat illness is related to the length of time core temperature is elevated, so rapid reduction and accurate serial measurements are crucial to prevention of organ system damage and death. The primary methods of patient cooling are conduction (ice-water immersion, cold packs) and convection (moisture and moving air). The choice of method used may depend on availability of equipment, but there is evidence that can guide optimal use of resources. This issue presents evidence-based recommendations and best practices in heat-illness resuscitation, including managing children who are obese, have special needs or take medications, and advocacy for prevention strategies.
Do Alternative Cooling Methods Have Effective Cooling Rates for Hyperthermia Compared With Previously Established CWI Cooling Rates? [2021]Clinical Scenario: In the last few years, there have been several studies examining alternative cooling strategies in the treatment of exertional heat stroke (EHS). Morbidity and mortality with EHS are associated with how long the patient's core body temperature remains above the critical threshold of 40.5°C. Although cold-water immersion (CWI) is the gold standard of treatment when cooling a patient with EHS, more recent alternative cooling techniques have been examined for use in settings where CWI may not be feasible (ie, remote locations). Clinical Question: Do alternative cooling methods have effective core body temperature cooling rates for hyperthermia compared with previously established CWI cooling rates? Summary of Key Findings: The authors searched for studies using alternative cooling methods to cool hyperthermic individuals. To be included, the studies needed a PEDro score ≥6 and a level of evidence ≥2. They found 9 studies related to our focused clinical question; of these, 5 studies met the inclusion criteria. The cooling rates for hand cooling, cold-water shower, and ice-sheet cooling were 0.03°C/min, 0.08°C/min, and 0.06°C/min, respectively, whereas the tarp-assisted cooling with oscillation (TACO) method was the only method that had an acceptable cooling rate (range 0.14-0.17°C/min). Clinical Bottom Line: When treating EHS, if CWI is not available, the tarp-assisted cooling method may be a reasonable alternative. Clinicians should not use cold shower, hand cooling, or ice-sheet cooling if better cooling methods are available. Clinicians should always use CWI when available. Strength of Recommendation: Five level 2 studies with PEDro scores ≥6 suggest the TACO method is the only alternative cooling method that decreases core body temperature at a similar, though slower, rate of CWI. Hand cooling, cold showering, and ice-sheet cooling do not decrease core body temperature at an appropriate rate and should not be used in EHS situations if a modality with a better cooling rate is available.